Method of and means for treating petroleum oils



Feb. 3, 1931. H; B. SETZLER ETAL 1,791,329

METHOD OF AND MEANS .FOR TREATING PETROLEUM OILS Filed 001?. 27, 1921 OIL 5UPPLY TANK 1 atented Feb. 3, 1931 UNITED STT'ES PATENT OFFICE HORACE B. SE'IZLER AND MEET C. MCDONALD, OF COFFEYVILLE, KANSAS, ASSIGNORS TO THE NATIONAL REFINING COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO METHOD OF AND MEANS FOR TREATING PETROLEUM OILS Application filed October 27, 1921.

Our invention relates to improvements in method of and means for treating petroleum oils and has primarily for its object the separation from heavy petroleum oil, whether 5 crude, raw, refined, semi-refined or diluted,

of the amorphous wax content or a part thereof. Our invention further contemplates improving the quality of lubricating oils and obtaining petrolatum as a by-product.

We have found that amorphouswax, solid parafiine hydro-carbons or petrolatum, as variously termed in the art, are removed with difficulty from petroleum oils, except under r conditions which we are herein broadly defining as constituting our improvements in the art. Contrary to prior practice, we have discovered that a large proportion of the amorphous wax content in petroleum oils may initially be separated out of such oils, prior to further treatment, by subjecting the oils at relatively low temperatures to the action of sulphuric acid in an agitator.

Briefly describing the process of our invention, we may state that the petroleum oil preferably is dehydrated and then chilled to the desired temperature by any suitable refrigerating means, after which said oil is subjectcd, in an agitator, to the action of concentrated sulphuric acid in calculated amounts. The petroleum oil, after treatment forthe necessary time in the agitator, will be found to have become clarified while the resulting sludge, upon settling out, will carry down with it a material percentage of the amorphous wax previously distributed throughout the body of the oil. The separation of the sludge from the oil, and the treatment of the resulting products do not concern the present invention and will not be set forth in detail.

Our improvements may be more readily explained in connection with the accompanying sheet of drawings, which diagrammatically sets forth apparatus of novel construction and arrangement for practicing our invention.

Referring more specifically thereto, and describing the prime purpose of the several 0 related appliances. A is the supply tank for any petroleum oil under treatment, with Serial No. 510,784.

which is connected a pump, B, for passing the oil to a dehydrating still C. A second pump D is interposed betweenstill C and refrigerating coils E fromwvhich a pipe E leads to the agitator F of novel construction, wherein our method is practiced.

This agitator is provided with an upper heat-insulated portion F and a lower jacketed portion F", containing brine for maintaining the contents of the agitator at a relatively low temperature. \Vithin the jacketed portion F there are provided coils Gr through which a refrigerant such as brine is adapted to be circulated by'means of pump G, connected in the pipe line with the brine tank H. A blower or compressor I, of the usual type, is connected with an air supply line 1', leading .to'the bottom of the agitator, wherein is exteriorly interposed a manifold I, also cooledby: the circulation of brine from tank H. ,Thus, the air supply in the agitator may be chilled previous to passing it through the oil under treatment within the agitator.

An acid supply line J also leads to the upper portion of the agitator, through which calculated quantities of acid may be introduced for the purpose of treating the oil.

From the foregoing. it will be seen that if desired, not only the oil supply in the agitator but the agitator itself and the air supply may be chilled below atmospheric temperature for the purpose of securing the necessary chemical reactions within the agitator at a relatively low temperature. Thus, instead of treating the oil Within the agitator at a temperature of from 100 F. to 200 F., as common practice requires for heavy oils, and at from 70 F. to 100 F., as common practice requires for light oils, we provide means for chilling the particular oil under treatment, both before its introduction to the agitator, as well as afterward, if desired, and we may subject it to an air supply either at atmosq Assuming that the agitator is charged with one thousand (1,000) barrels of mid-continent crude oil at 35 F., the blower is started, and after a minute or two the calculated supply of sulphuric acid having previously been determined, at thirty pounds (30: 3:) to the barrel of oil charged, the acid is blown or pumped into the agitator in the known manner, consuming approximately ten to fifteen minutes therefor. Necessarily, the

temperature of the oil is materially raised,

since we preferably employ concentrated sulphuric acid 66 B. specific gravity, or sulphuric acid of any higher strength which comes under the trade name of Oleum, known as 57 10% and up to and above Oleum.

In order to counteract this rise in'temperature, which may amount to from ten to fifteen degrees, we may employ the refrigerating means which are shown, associated not only with the agitator itself, but with the air supply, although we do not necessarily depend upon any further refrigerating action than that to which the petroleum oil is initially subjected. However, it is obvious that the tendency to higher temperatures may be more or less neutralized by the coils G, for

cooling the contents of the agitator, while a' chilled air supply through the pipe line I, similarly will carry off large volumes of heat, so that the treatment of petroleum oil may be conducted within a range of low temperatures well within the control of the operator.

lVith mid-continent crude oil, the blower is operated for a period of approximately an hour and a half to two hours, whereby the crude oil is thoroughly subjected in minute particles to the finely sub-divided particles of acid and the well known reactions take place by which the undesirable hydro-carbons are converted into sludge, the color and odor of the crude oil are materially. improved. This marked improvement in the color, resulting in the production of an exceptionally bright stock, arises not only from the removal of the heavier and darker portions of the hydrocarbons, but the crude oil itself is much better clarified and improved by the action of the sulphuric acid when in chilled condition. Moreover, the petr latum or amorphous wax. is so reacted upon by the acid at lowered temperatures as to be readily separated in large measure from the body of the clarified oil through precipitation with the sludge.

Upon shutting down the blower, it will be found that approximately two hundred (200) barrels, more or less, of sludge will settle into the lower stratum of the agitator, when the sludge acid may be promptly drawn off or the contents may be allowed to stand as long as desired, say forapproximately twentyfour (24) hours to effect substantially complete separation.

Following the foregoing critical steps, the sludge is drawn olf and treated in any well known manner for separating all the petrolatum, while the oil is transferred into another agitator where it is subjected to the equally well known alkaline treatment. Neither of the foregoing methods require discussion in the present specifications, for the reason that they do not immediately concern the invention which we have herein explained.

As a further step, for the purpose of producing exceptionally bright stock directly from the crude oil, we may alternatively draw off the sludge first produced, and subject the remaining eight hundred (800) barrels of treated crude oil to an additional charge of concentrated sulphuric acid as above, em-

ploying, for the purpose, approximately from live pounds (5#) to thirty pounds (30#) per barrel in the secondary treating of the oil. The initial temperature of said oil, may be maintained or reduced, as-previously explained, by circulating brine through the pipes G, so that the renewed blowing will be conducted at a temperature sufficiently low to effect the further separation of any remaining amorphous wax or petrolatum in the oil. However, this further treatment is not ordinarily necessary in practicing our invention, and we merely advert thereto in order to explain the possibilities of continued treatment, resulting in the production of a relatively small volume of sludge, but with a corresponding improvement in the refinedproduct.

Except for the modifications in the air blower, which are desirable in practicing our improvement, and the addition of refrigerating systems to the oil and air supply lines, our apparatus herein disclosed does not vary from ordinary practice. However, we desire to point out that, in addition to the jack eted portion of the agitator containing the brine enclosed pipes G, we preferably cover the dome and upper side portions of the agitator with any suitable heat insulating materials, J, such as cork or asbestos, whereby the temperature of the agitator may more readily be controlled.

W'i reference to the lrine tank H, dia- Moreover,

- following:

grammatically shown in the drawing, we may point out that this is chilled in any desired manner such as by the expansion of anhydrous ammonia, carbon dioxide or even by salted ice; the necessary chilling forming no part of the novelty herein claimed and all apparatus set forth, except as specifically claimed, being of such design and construc-, tion as is well known in the related arts.

With reference tothe defined method specifically set forth above, we may state that it is our intention to illustrate the practice of our improvement in a'manner which will be understood by those skilled in the art, as relating to any heavy oils, to wit: crude, light and heavy neutrals, tar oils, residues from crude and asphaltum, wax oil, wax and pressed oils, either diluted or undiluted. These oils are treated by us in the agitator at a temperature belou that previously defined for the treatment of light oils, ranging from F. to zero, whereby the amorphous wax, coloring matter and undesirable hydro-carbons may be eliminated in greater or less measure from such heavy oils. It will be understood that the light oils do not contain sufiicientamorphous wax to require the'chilling treatment which we have herein described and set forthat the preferred range of from 30 F. to 40 F. This, we believe to be the most practicable initial temperature for producing the highly desirable results herein indicated.

Each particular oil obviously requires analysis for the purpose of determining the amount of acid necessary for practicing our treatment, rangin per barrel ,from five pounds (5#) to fifty pounds (50#) of concentrated sulphuric acid of 66 Be. specific gravity or Oleum of 5%, 10%, 15% up to 50% or above, the stronger acids producing a higher degree of refinement in the finished product.

Accordingly, in the specification and claims, we have adopted the term petroleum oils as a generic definition of such heavyoils which we propose to treat in the novel manner herein set forth and claimed. we have adopted the term chilled, as used in our claims, as descriptive of a process requiring a mean working temperature in the agitator of from 30 F. to 40 F., as indicated above.

Having now described an illustrative method of practicingour invention, we claim as new and desire to secure by Letters Patent,

together with such modifications thereof as may be made by those skilled in the art, the

1. The herein described method of treating petroleum oils containing amorphous wax, which consists in subjecting the'selected oil at a temperature below 40 F. to the continued action of sulphuric acid, whereby the fluid constituents may be approximately freed from the amorphous wax content, substantially as set forth.

2. The herein described cold method of treating petroleum oils, which consists in reducing the temperature of the oil approximately to 40 F., agitating the oil, subjecting it while chilled during continued agitation to the action of sulphuric acid, and separating clarified fluid constituents and sludge, sub-stantially as set forth.

3. The herein described method of treating heavy petroleum oils containing amorphous wax, which consists in chilling said oil to a temperature below 40 F., and subjecting it to the action of sulphuric acid and oleum while agitated, whereby the fluid constituents of the oilmay be approximately freed from the amorphous wax content, and the color and characteristics of the oil improved, substantially as set forth.

4. The herein described method of treating heavy petroleum oils containing amorphous wax, which consists in chilling the selected oil to an initial temperature ranging between 30 F. and 40 F, subjecting the oil while chilled to the action of concentrated sulphuric acid, agitating the oil and acid to precipitate the sludge and amorphous wax and separating the oil and semi-solid constituent, substantially as set forth. I

In testimony whereof we do now ailix our signatures.

' HORACE B. SETZLER.

MERT C. MCDONALD. 

